Thermal sensing blow out preventer actuating device

ABSTRACT

The present disclosure is directed to a fail safe device to close an oil or gas well that has ignited during drilling or workover operations working in conjunction with pressure accumulators and blow out preventers. The apparatus is installed in a line the upstream side of which is pressurized by the accumulators and the downstream side of which is connected to actuate the blow out preventer. The device has a pair of normally closed check valves which are spaced apart but which may be moved together to unseat the valves and permit the pressurized fluid from the accumulators to actuate the blow out preventer. The movement of the check valves by a fluid motor which while being under pressure is restrained from unseating the valves by a thermally fusible flowable barrier which when attaining flow temperature will permit the fluid motor to actuate and unseat the normally closed check valve and apply the accumulator pressure to actuate the blow out preventer to close the well.

llnited States Patent Milsted, Sr.

[ 1 Mar. 2%, 1972 [54] THERMAL SENSING BLOW OUT PREVENTER ACTUATING DEVICE James Leland Mllsted, Sr., 537 Olive Street, Harvey, La. 70058 Apr. 29, 1970 [72] Inventor:

[56] References Cited UNITED STATES PATENTS 3/1954 Hebert ..l37/72 12/1965 l-laeber ....251/1X Primary Examiner-M. Cary Nelson Assistam Examiner-Richard Gerard Attorney-Wilkinson, Mawhinney & Theibault [5 7] ABSTRACT The present disclosure is directed to a fail safe device to close an oil or gas well that has ignited during drilling or workover operations working in conjunction with pressure accumulators and blow out preventers. The apparatus is installed in a line the upstream side of which is pressurized by the accumulators and the downstream side of which is connected to actuate the blow out preventer. The device has a pair of normally closed check valves which are spaced apart but which may be moved together to unseat the valves and permit the pressurized fluid from the accumulators to actuate the blow but preventer. The movement of the check valves by a fluid motor which while being under pressure is restrained from unseating the valves by a thermally fusible flowable barrier which when attaining flow temperature will permit the fluid motor to actuate and unseat the normally closed check valve and apply the accumulator pressure to actuate the blow out preventer to close the well.

7 Claims, 6 Drawing Figures PmENTEnmARza m2 3, 651 ,823

SHEET 1 OF 3 INVLA' I (1; H

JAMES L M/LS TE D SR ATTORNEYS THERMAL SENSING BLOW OUT PREVENTEIR ACTUATING DEVICE The present invention is directed to the quick shutdown or closing of an oil or gas well when a fire occurs and which will happen automatically actuating the blow out preventers when a predetermined temperature rise on the rig occurs.

Another object of the present invention is the provision of a quick closing thermally responsive device which has fail safe features which will insure against the fortuitous and untimely closing of a well.

Another object of the present invention is the provision of a pair of normally closed check valves in a fluid pressurized line to actuate the blow out preventer which valves are actuated by a fluid motor under the influence of the liquid pressure which actuates the blow out preventer but which motor is restrained from acting on the valves by a thermally fusible flowable barrier.

A still further object of the present invention is the provision of an automatic blow out preventer actuator which will function to close the well when temperatures because of tire prevent human beings from operating the normal manual cntrol valves.

A still further object of the invention is the provision of a fluid motor restraining device in the form of an epoxy resin which when cold will have the strength to resist accumulator pressure but which when heated to 400F. will become flowable and permit the fluid motor to unseat normally closed valves to actuate the blow out preventer.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawings wherein like symbols refer to like or corresponding parts throughout the several views.

FIG. 1 is a schematic view of an oil well drilling rig showing the Christmas Tree, blow out preventers, accumulators and manual remote operating stations for the blow out preventer actuating controls as well as locating the apparatus of the present invention with respect thereto.

FIG. 2 is a fragmentary perspective view of the four way control valve manual operation on the accumulator platform.

FIG. 3 is a hydraulic schematic of the operation of the four way valve of FIG. 2.

FIG. 4 is a vertical section taken through the apparatus of the present invention with the two normally closed check valves in their mated open position.

FIG. 5 is a side elevational view of the apparatus of FIG. 4.

FIG. 6 is a vertical section taken through a modified form of apparatus constructed in accordance with the present invention.

Referring now for the moment to FIG. 1, an oil well rig is shown having a Christmas Tree arrangement 10 with the blow out preventers 11, 12 and 13 thereon. The motive fluid for actuating the blow out preventers comes from a source of hydraulic accumulators 14 which will bring up the hydraulic lines to a pressure adequate to assure operation of the blow out preventers.

The overhead rig structure of 15 has a manual remote control station 16 for operating the control valves for closing the blow out preventers.

in the oil well rig structure 15 the apparatus of the present invention is shown schematically as being located at 17 and which is shown being coupled to the hydraulic accumulator pressurized source at one side and to the blow out preventers downstream of the apparatus.

Referring now to FIGS. 4 and 5, the thermo-sensing blow out preventer actuating device 17 has an end portion 18 having a bore 19 therethrough. An O-ring seal 20 permits of hydraulic communication between the bore 19 and the bore 21 and the cylinder housing 22. A cylinder chamber 23 is provided in which is mounted a piston 25 having a rod 26 which is provided with a hollow bore 24 therethrough. The piston rod 26 has a projection 27 annularly thereabout. The operating end of the piston rod 26 has connected thereto a normally closed check valve 28 which is in axial alignment with a normally closed check valve 29 carried by the upper casement 30. The upper casement 30 has an opening 31 therethrough. This structure provides for a fluid path straight through the device obstructed only by the two normally closed check valves 28 and 29. The fluid path is through bore 19, bore 21, bore 24 through the piston rod 25 and 26 up to the check valve 28. The fluid passage on the downstream side of the check valves is shown at 31 and from 31 goes directly to the fluid operating connection of the blow out preventers. The two normally closed check valves 28 and 29 are arranged such that upon mating the two valves 28, 29 each valve unseats the other to permit the head of the fluid pressure to go from the end 18 through the end 30 of the thenno-sensing blow out preventer actuating device 17.

The annular extension 27 carried by the piston rod extension 26 is position to engage a ring 32 which forms a base for a pair of telescopic tubes 33 and 34. The walls of the tubes 33 have openings 35 therethrough and the tube chambers are normally filled with an epoxy resin of sufficient volume to cause the two normally closed check valves 28 and 29 to be separated; however, upon the epoxy resin attaining a temperature in excess of 400F. the resin will become flowable and will flow through the openings 35 allowing the fluid motor piston 25 to move the rod 26 and thereby cause the valve 28 to mate with the valve 29 opening both valves and allowing the pressurized fluid from the accumulators 14 to actuate the blow out preventers and to thereby seal off the well 12. The upstream side of the unit 17 is in communication with the pressure fluid from the accumulators l4 and upon the opening of the check valves 28, 29 the fluid will flow through line 37 to the blow out preventer 13 to seal the well.

Referring now to H6. 6, 40 designates a modified form of thermo-sensing blow out preventer actuating device in which a cylinder 41 has a fluid chamber 42 in communication with the pressurized fluid from the accumulators 14 through opening 43. Within the cylinder 41 is a piston 44 having a rod 45 with an open bore 46 therethrough. The other end of the hollow piston rod 45 has connected thereto a normally closed check valve 47 which can only be unseated by mating it with a complemental normally closed check valve 48 carried by a static portion 49 of the cylinder 41 so that upon unseating of both valves 47 and 48 fluid will flow through the unit 40 and be communicated to actuate the blow out preventer 13 through line 50.

Carried on the piston rod 45 is an annular projection 51 which engages a thermal sensing fusible flowable barrier 52 of an epoxy resin which will flow only upon the resin being heated to over 400F. at which time the head pressure upon the piston from the accumulators 14 will cause the projection 51 to force the flowable epoxy through the openings 53 in the cylinder walls thereby permitting the hollow piston rod 45 to cause mating and unseating of the two normally closed check valves 47, 48 which will permit the pressurized fluid to pass from the accumulators to actuate the blow out preventers to seal the well. In this embodiment the check valves 47, 48 are identical to the check valves 28, 29 of FIGS. 4 and 5.

The parts 18, 22 and 30 are retained in operative relationship by assembly bolts 36, and nuts 37.

In both embodiments the cylinder walls 22 and 41 respectively have high velocity check valves 54 which leak until a velocity is applied at which time they hold pressure. This prevents hydraulic fluid that might leak past the piston seal ring from causing a hydraulic lock when the piston head moves toward the check valve operating position.

While 1 have given as an example an epoxy resin which will become flowable at 400F. or over for a form of thermally fusible flowable barrier it will be appreciated by those skilled in that art that any fusible flowable solid which will liquify or become flowable may be employed whether it be metallic or plastic so long as it has strength in its solid state to overcome the hydraulic head and keep the valves 28, 29 and 47, 48 apart and closed but which will upon being heated become flowable allowing the hydraulic head to move the piston rod a length sufficient to mate the normally closed valves thereby unseating them and allowing the hydraulic head pressure to flow to the blow out preventer and seal off the well.

While drilling or during workover the devices 17 or 40 may be mounted anywhere on the drilling or workover rig, probably about 20 feet above the floor, in the derrick 15. A line A is installed from the pressure accumulator 14 to one end of the unit 17. Another line B is installed from the downstream side of the unit 17 to the blow out preventer 13. Both lines A and B are in parallel to the operating valves at the remote station 16 and are connected to supply operating fluid to the blow out preventer.

The output line 31 of unit 17 and output line 50 of unit 40 may be connected to the piston operator 56 attached to the handle 57 of the four-way control valve 58. Normally the piston 56 is used to shift positions of the four-way valve 58 remotely. The four-way control valve 58, shown in FIGS. 2 and 3 are shown diagramatically at 16 in FIG. 1 and over ridden to actuate the blow out preventer by the unit 17 when a rise in ambient temperature occurs by a fire which due to heat intensity makes it impossible for a human being to actuate the valve 58 to close the blow out preventers 11, 12 and 13.

What I claim is:

1. For use with a volatile fluid well rig having a blow out preventer thereon coupled to a source of fluid supply under pressure to actuate a blow out preventer, a thermal sensing blow out actuator actuating device comprising a first cylinder adapted to be placed in communication with the pressure to actuate a blow out preventer, a first piston in said first cylinder subject to said pressure and communicating with a first normally closed check valve carried by said piston, a second piston actuatable by said first piston, thermally fusible means responsive to ambient temperature conditions positioned to restrain movement of said first and second piston means and being accessible to surrounding ambient temperature to become flowable above 400 F. to escape and permit movement of said first piston, and a second normally closed check valve mounted on a static part of said device adapted to be placed in fluid circuit to actuate a blow out preventer and positioned to be engaged by said first normally closed check valve so that upon said first normally closed check valve engaging the second normally closed check valve both check valves are unsealed to permit the fluid supply to actuate a blow out preventer upon flow of the fusible means.

2. For use with a volatile fluid well having a blow out preventer supplied with actuating fluid from a source under pressure through a main conduit under control of a hand-actuated valve in the conduit, an automatic heat-triggered device adapted to be placed in a by-pass conduit connected to the main conduit at opposite sides of the hand-actuated valve and in communication at an initial end with the pressure fluid source and at the discharge end with a blow out preventer, comprising a. a pair of normally closed check valve means adapted to be placed in communication with a by-pass conduit,

b. fluid-pressure motive means adapted to be subjected to the pressure in a by-pass conduit to be automatically moved thereby and relatively to the last-mentioned valve means to engage and open said check valve means when so moved, and

c. a normally solid blockading material in the path of movement of the motive means subject to melting at elevated temperatures to automatically permit movement of the motive means to open said check valve means.

3. For use with a pressurized fluid charged line for actuating blow out preventers on a volatile fluid well, a thermal sensing blow out preventer actuating device comprising, two normally closed check valves positioned with their central axis on the same center line but physically separated so that each normally remains closed but which when opened will pass actuating fluid, fluid motor means in fluid circuit with and subjected to the ressure of the chaglged line and being connected to said norm ly closed check v ves for opening same, and a fusible flowable barrier means responsive to ambient temperature conditions positioned to normally restrain the fluid motor constantly subjected to charged pressure from opening said check valves to pass pressure actuating fluid through the line until a rise in ambient temperature renders the barrier flowable and permits the fluid motor to actuate and open said check valves to pass the pressurized actuating fluid.

4. The apparatus of claim 3 wherein the fluid motor comprises a cylinder, a piston having an open ended hollow rod one end of which is in communication with the pressurized fluid at the head end of the cylinder and the other end of which is connected to one of said normally closed check valves, fusible flowable barrier engaging means on said piston rod positioned to engage said barrier and restrain linear motion of said piston rod against the pressurized fluid until said barrier becomes flowable which permits movement of one of said check valves against the other of said check valves to unseat both valves and to pass the pressurized fluid through the piston rod and both of said check valves upon flowing of the fusible barrier.

5. The apparatus of claim 4 wherein the fusible barrier is of an epoxy resin which becomes flowable above 400 F.

6. The apparatus of claim 5 wherein the fusible barrier comprises rods of epoxy resin which is flowable above 400 F. in at least one pair of telescopic tubes one of each pair of which is connected to a static part of the device and the other of each of which is connected to the barrier engaging means of the piston rod of said motor and wherein at least one of said tubes of each pair has openings through the wall thereof to permit escape of the epoxy when it reaches flow temperature against the head pressure acting on the piston rod.

7. The apparatus of claim 5 wherein the fusible barrier is a zone of epoxy resin which is flowable above 400 F. about the piston rod and which is engaged by an annular projection carried by said piston rod and wherein a plurality of openings are provided through the cylinder wall in the area of the barrier so that upon said barrier becoming flowable the annular projection on said rod will force the flowable epoxy through the openings and permit the piston rod to shift under its pressurized head causing the two check valves to unseat and pass the pressurized fluid to actuate the blow out preventer. 

1. For use with a volatile fluid well rig having a blow out preventer thereon coupled to a source of fluid supply under pressure to actuate a blow out preventer, a thermal sensing blow out actuator actuating device comprising a first cylinder adapted to be placed in communication with the pressure to actuate a blow out preventer, a first piston in said first cylinder subject to said pressure and communicating with a first normally closed check valve carried by said piston, a second piston actuatable by said first piston, thermally fusible means responsive to ambient temperature conditions positioned to restrain movement of said first and second piston means and being accessible to surrounding ambient temperature to become flowable above 400* F. to escape and permit movement of said first piston, and a second normally closed check valve mounted on a static part of said device adapted to be placed in fluid circuit to actuate a blow out preventer and positioned to be engaged by said first normally closed check valve so that upon said first normally closed check valve engaging the second normally closed check valve both check valves are unseated to permit the fluid supply to actuate a blow out preventer upon flow of the fusible means.
 2. For use with a volatile fluid well having a blow out preventer supplied with actuating fluid from a source under pressure through a main conduit under control of a hand-actuated valve in the conduit, an automatic heat-triggered device adapted to be placed in a by-pass conduit connected to the main conduit at opposite sides of the hand-actuated valve and in communication at an initial end with the pressure fluid source and at the discharge end with a blow out preventer, comprising a. a pair of normally closed check valve means adapted to be placed in communication with a by-pass conduit, b. fluid-pressure motive means adapted to be subjected to the pressure in a by-pass conduit to be automatically moved thereby and relatively to the last-mentioned valve means to engage and open said check valve means when so moved, and c. a normally solid blockading material in the path of movement of the motive means subject to melting at elevated temperatures to automatically permit movement of the motive means to open said check valve means.
 3. For use with a pressurized fluid charged line for actuating blow out preventers on a volatile fluid well, a thermal sensing blow out preventer actuating device comprising, two normally closed check valves positioned with their central axis on the same center line but physically separated so that each normally remains closed but which when opened will pass actuating fluid, fluid motor means in fluid circuit with and subjected to the pressure of the charged line and being connected to said normally closed check valves for opening same, and a fusible flowable barrier means responsive to ambient temperature conditions positioned to normally restrain the fluid motor constantly subjected to charged pressure from opening said check valves to pass pressure actuating fluid through the line until a rise in ambient temperature renders the barrier flowable and permits the fluid motor to actuate and open said check valves to pass the pressurized actuating fluid.
 4. The apparatus of claim 3 wherein the fluid motor comprises a cylinder, a piston having an open ended hollow rod one end of which is in communication with the pressurized fluid at the head end of the cylinder and the other end of which is connected to one of said normally closed check valves, fusible flowable barrier engaging means on said piston rod positioned to engage said barrier and restrain linear motion of said piston rod against the pressurized fluid until said barrier becomes flowable which permits movement of one of said check valves against the other of said check valves to unseat both valves and to pass the pressurized fluid through the piston rod and both of said check valves upon flowing of the fusible barrier.
 5. The apparatus of claim 4 wherein the fusible barrier is of an epoxy resin which becomes flowable above 400* F.
 6. The apparatus of claim 5 wherein the fusible barrier comprises rods of epoxy resin which is flowable above 400* F. in at least one pair of telescopic tubes one of each pair of which is connected to a static part of the device and the other of each of which is connected to the barrier engaging means of the piston rod of said motor and wherein at least one of said tubes of each pair has openings through the wall thereof to permit escape of the epoxy when it reaches flow temperature against the head pressure acting on the piston rod.
 7. The apparatus of claim 5 wherein the fusible barrier is a zone of epoxy resin which is flowable above 400* F. about the piston rod and which is engaged by an annular projection carried bY said piston rod and wherein a plurality of openings are provided through the cylinder wall in the area of the barrier so that upon said barrier becoming flowable the annular projection on said rod will force the flowable epoxy through the openings and permit the piston rod to shift under its pressurized head causing the two check valves to unseat and pass the pressurized fluid to actuate the blow out preventer. 